Oral contraceptives and hypertension.

Oral contraceptives result in a mild elevation of blood pressure in most women and overt hypertension in about 5%. Both estrogen and progestogen are responsible for the blood pressure effect, but the mechanism is as yet unknown. The risk of cardiovascular complications is found primarily in women over 35 years of age and in those who smoke. Preparations with an estrogen content of 30 g and a progestogen content of 1 mg or less appear to be safe.